Summary/ Abstract In a lower middle-income country (LMIC) such as Nigeria where child and adolescent mental health (CAMH) services are available but limited, guardians? willingness to utilize accessible treatment for their children is pivotal to ensuring that their mental health (MH) needs are met in a timely manner. However, it remains unclear how socio-cultural and individual factors interact in complex ways to influence guardians? decision to utilize the few CAMH services that are accessible. A theoretical framework is crucial for guiding the development of interventions that strategically address barriers to care. Community-based participatory (CBP) approaches that engage parents in the conception, development, and delivery of interventions have been established in various settings yet implementing such methods have been difficult in regions where rigorous process and outcome evaluations are lacking. Notwithstanding the dearth of current MH services in Nigeria, an anticipatory understanding of factors that influence guardians? willingness to utilize accessible services for their children with MH needs will provide critical direction for the development of theoretically driven and locally based interventions that optimize CAMH care in regions where MH services remain underutilized. Therefore, our research teams from Howard University (HU) and the University of Ibadan (UI) will identify determinants of guardians? willingness to utilize accessible CAMH services for their children in Ibadan, Nigeria. The scientific aims of this 3-year study are to: (Aim 1) empirically test the CAMH Help Seeking Model developed by the UI research team that explains the interactive pathways of socio-cultural and individual factors that influence guardians? willingness to utilize accessible MH services for their children at the University College Hospital in Ibadan (UCH). To meet this aim, a stratified two-stage cluster sample of 250 adult guardians of children 5 to 19-years-old living within 25km from UCH will be interviewed with standardized measures; and to (Aim 2) develop and evaluate a community-based participatory intervention that will be principally guided by the model we test and confirm in Aim 1. To meet this second aim, ten guardian consultants will co-develop and co- implement a group intervention whose goal is to increase 100 guardians? willingness to use accessible services at UCH. Results from this study will empirically identify pathways that influence guardians? willingness to utilize accessible CAMH services and help guide strategies to reduce CAMH disparities in LMICs. In addition, the current study will address a critical need to strengthen the methodological rigor of CBP programming that aims to reduce MH disparities in LMICs such as Nigeria by developing and evaluating a community intervention that is theoretically informed and locally-implemented by guardians. Ultimately, this study will enhance the global MH research infrastructure and student mentoring capacity in the Department of Psychology at Howard and will further provide the groundwork for a larger follow-up collaborative study with UI to evaluate the scalability and sustainability of a CBP intervention that addresses CAMH help-seeking behavior.